The present invention relates to improvements in apparatus for setting anchor bolts, and the like, in a concrete slab.
In the construction industry, it is common to use threaded anchor bolts set in concrete slabs to attach the base plate of a column in position. These base plates have flanges with a particular hole pattern therein through which the anchor bolts extend. Lock nuts on the anchor bolts are positioned above and below the base plate and are used to provide a system for attaching the columns to the slab.
It is conventional to set these anchor bolts in concrete slabs by first pouring the concrete and then inserting the anchor bolts in the concrete. In the setting of these anchor bolts, it is important that the anchor bolts be properly located in the concrete so that the columns will be in the proper position and so that the bolts will mate with the hole pattern of the column base plate.
Therefore, a means for accurately positioning these anchor bolts in the slab with a minimal amount of labor and expense is highly desirable.
Therefore, according to one embodiment of the present invention, an improved supporting apparatus is provided. The apparatus has a rigid plate with a plurality of elongate legs extending from one side thereof. Bores are formed through the plates for attaching a wooden block to the other side of the plate by fasteners extending through the bores. The support is positioned in the area where the anchor bolts are to be set in the concrete. The legs of the support are embedded in the subgrade of the slab until the upper surface of the plate is flush with the level of the upper surface of the slab.
Thereafter, a template carrying a plurality of anchor bolts is positioned on and supported from the upper surface of the wooden block with the anchor bolts in their desired ultimate position. A finishing nail can be driven into the block through a referencing hole in the template. Thereafter, the template is removed and concrete is poured into the form and around the support. Before the concrete sets, the template is positioned with the nail extending through the referencing hole to return the template to the desired position with the anchor bolts inserted into the concrete. After the concrete has set, the template is removed and the wooden block is detached from the support, leaving a properly positioned set of anchor bolts for attaching a column in place upon the slab.
In accordance with another embodiment of the invention, a form is provided and is supported from the apparatus to form a depression in the slab around the anchor bolts.